1. Field of the Invention
The present invention relates to an image forming apparatus having an image editing function and, in particular, an image editing function-equipped image forming apparatus which, in a digital copying machine for reading an image in dot units and copying it on a sheet, can edit an image by designating an editing range for, for example, trimming, masking or centering.
2. Description of the Related Art
Known as a conventional image forming apparatus is a digital copying apparatus equipped with an image editing function for, for example, trimming, masking or centering. In the copying apparatus of this type, editing is normally performed on a document through the designation of that editing range and a corresponding image is processed based on the designated range. An apparatus has already been proposed in which a marker pen is used as a means for designating such an editing, etc.
In such proposed image forming apparatus, an editing range cannot be designated on a document unless a given marker pen, or color, specific to the apparatus is employed. In the case where the editing range is designated by other than the specific marker pen or color, there is a problem that the apparatus neither recognizes the editing range nor generates an edited image. Consequently, the user of the apparatus has to carry a specific spare marker pen with him or her or interrupt an editing operation until the specific marker pen is available. Therefore, the apparatus is not user-friendly and there is room for improvement.
There is a growing demand for an editing function-equipped image forming apparatus of such a type that, even if the editing range is not specified by a specific marker pen, it is still possible to register a general-purpose marker pen as a marker pen for editing on the image forming apparatus and to perform an editing operation with the use of such a registered marker pen.